Grain separator



y 1943- H. MJoLsNEss 2,318,250

GRAIN SEPARATOR Filed March 1, 1941 2 Sheets-Sheet 1 rwe/wto'n HAAKON MJOLSNESS, (DECEASED), BY OLGA A. MJOLSNESS EXECUTRIX 4, 1943. I H. MJOLSNESS 231,250

GRAIN SEPARATOR Filed March 1, 1941 2 Sheets-Sheet 2 QIWM'VM HAAKON MJOLSNESS, (DECEASED),BY

QLGA A. MJOLSNESS, EXECUTRIX I[Il 4L @3143 Patented May 4, 1943 GRAIN SEPARATOR' Haakon Mjolsness, deceased, late of Minneapolis,

Minn, by Olga A. Mjolsness, executrix, Minneapolis, Minn.

ApplicationMarch 1, 1941, Serial No. 381,322

2 Claims.

This invention relates to an improvement in grain separators wherein it is desired to provide'a grain separator which will remove all of the impurities from. grain, such as wheat or the like. In previous application, Serial No. 91,146, now Patent 2,211,575, granted August 13, 1940, the inventor discloses a grain separator having vertical rotary screen therein using inclined brushes against the surface of the screen to retard the flow of grain about the screen. While this device has been found entirely practical and has been in operation successfully for a considerable period of time, it has been found that large heavy objects, such as stones and the like, have a tendency to strike the lower end of the inclined brushes and to remain in this position until manually removed. By stopping the machine occasionally and cleaning the same, the former device may be maintained in perfect operating condition unless the grain being cleaned has a high percentage of heavy'impurities therein.

In order to prevent the necessity of providing inclined brushes and in order to save the cost of these brushes and the upkeep thereof, it is a purpose of the present invention to provide an extra contact of the grain with the cylinder and to so arrange the screen that all of the grain comes in contact with the screenthrough two revolutions of the grain rather than through a single revolution. Thus all of the grain is urged 3 into contact with the screen and a proper separation of the materials may take place without the use of the inclined brushes for retarding purposes. 1

It is a feature of the present invention to introduce the grain upon a ring-shaped platform encircling the screen which is sealed with respect to the screen by providing a packing member on the shelf engageable with an unperforated portion of the screen. The grain is carried about the circumference of the screen by the rotation. of the, screen, insuring a contact of all of the grain with the screen. After the grain has rotated virtually an entire revolution, the grain drops upon a second ring-shaped shelf andis again carried about the circumference of the separator by action of a lower perforated strip on the screen. thus providing greater contact between the grain and the screen. The inventor has found that with this arrangement all of the impurities may be effectively removed and the grain to be cleaned may all have an opportunity of passing through the screen. 7

It is a further object of this invention to provide a screen which is provided with pockets or indentations having openings therethrough similar to those shown in the previous application above described. In contrast with the previous construction, however, the lower rows of openings most closely adjacent the uppermost shelf supporting the grain as it enters the separator,

are plain openings through the screen rather than pocketed openings. One of the objects of the pocketed openings is to revolve the kernels and to carrythese kernels around the circumference of the screen together'with the screen.

The inventor has found, however, that by formingtwo rows of plain perforations through the screen above'the uppermost shelf and'by having all piain'openings through the screen adjacent the second shelf to which the grain is fed, thegrain is carried more slowly about the circum dicated by the line 2-2 of Figure 1.

Figure 3 is a transverse section through the separator, the position of the section being indicated by the line 3-3 of Figure 2'. i

Figure 4 is a detail view of a portion of 'th screen adjacent the upper shelf, showing the construction of the screen.

' The separator A is-in general of the form 11- lustrated in the 'co-pending application above referred to. This separator includes a vertical cylindrical. casing l9 having a reinforcing flange 5 i encircling the base thereof and having a floori2 positioned adjacent the bottom of the casing. A transmission 13 is mounted upon the flooring I2. This transmission acts to transmit motion from the horizontal shaft It to the vertical shaft l5 and in most-instances to reducethe speed of the shaft l5 with respect to the shaft hi. A drive pulley I6 is mounted upon the'shaft it designed to be rotated by any suitable source of power and movement imparted the shaft, M

by rotation of the pulley l6 drives the vertical shaft l5.

The vertical shaft I5 engagesa socket ll ofa spider 19 which supports paddles 20 which in turn support a disc-shaped horizontal seed screen ZL' The seed screen 2| rests upon the paddles 2t and forming a part of this spe sleeve 43.

openings through the screen are maintained open by these paddles. A shaft 22 also engages in the socket or hub l1 and is rotated in unison with the hub and the shaft I5. The shaft 22 is coaxial with the shaft I and is separate therefrom so that this shaft may be raised above the screen 2| so that this screen may be removed through the side of the cylindrical casing ID. A slot 23 is formed in the casing for the removal of screen 2| and a two-part band 25 encloses the slot when the machine is in operation. An agitator 26 is mounted upon the shaft 22 above the screen 2| and acts to agitate grain over the surface of the screen 2 I. The agitator 26 is not in contact with the screen but contacts the grain resting thereupon. Also rotatable with the shaft 22 the inventor provides a cone-shaped duplicator 21 which is connected by spaced arms 29 to a cylindrical shell 39. The shell 30 is provided. with an inwardly extending flange 3| thereupon which is designed to extend into close relationship with a cone 32 floatingly supported in a manner which will be later described.

The shell 3|! supports the cylindrical screen 33 which is reinforced at its upper edge by a rim 34. The screen 33 is provided with an unperforated band 35 separating a perforated upper portion 36 and a perforated lower portion 31. The perforations in the upper portion 35 of the screen are formed in cup-shapedindentations 39 with the exception ofthe lowermost two or three rows 4!) of the upper section of the screen which are merely perforations through the screen. All of the perforations 4| in the lower portion 31 of the screen are merely plain perforations through the screen and have no pockets for indentations adjacent the same.

The upper extremity of the casing H] is closed by means of a top closure 42 which is ring-shaped and which encircles the central vertical tubular A hopper 44 leads to the space between the casing I0 and thescreen 33 and the entrance into the separator is regulated by means of an adjustable gate 45. A series of angularlyshaped links 45 are secured at 41 to the top 42 of the casing l3 and are pivotally secured at 49 to the cone-shaped deflector 32. This deflector 32 forms an automatic feed for grain passing through the screen 33 as an increased friction on this screencauses rotation thereof which twists the links 46 and acts to raise the deflector 32. A central sleeve 50 on the top of the deflector 32 telescopes with relation to the sleeve 43 to form a continuous air passage therethrough. This air passage leads to the interior of a rotatable deflector 5| which changes the direction of the air passing upwardly through the sleeves 53 and 43 to separate the-larger portions of the lighter material which are drawn from the grain by the aspirating process.

Agitators 52 are mounted upon the shaft 22 together with the deflector 5| so that the larger particles separated from the air may be moved toward a suitable outlet in this aspirating chamber 53. The chamber 53 is cylindrical and is of the same diameter as the casing l0 and is supported above the casing Ill by suitable spacing supports 54.

The top of the aspirating chamber 53 is provided with a top closure 55 which is ring-shaped and which accommodates the elbow 56. The elbow 56 leads to the entrance of a fan 51 rotated by the pulley 59; A belt 60 connects the pulley 59 with. a pulley-6| on thedrive shaft l4 to drive the fan 51. Air is drawn through openand the casing in.

ings 62 in the side of the casing l0 through the grain dropping between the inturned flange 3| on the sleeve 30 and the deflector 32 and all of the lighter material in the grain iscarried upwardly through the sleeves 50 and 43 and through the deflector 5| into the aspirating chamber 53. The heavier particles of this lighter material are separated out in this chamber, while the remaining impurities are blown to a suitable dust collector connected with the fan.

Encircling the unperforated base of the screen 33, the inventor provides a shelf 63 which supports a sealing element 64 which engages the outer surface of the screen 33. A second upper shelf 65 which is also ring-shaped encircles the screen 33 and a sealing element 66 engages the unperforated portion 35 of the screen 33. The upper shelf 65 is provided with an opening 61 therein through which any material not passing through the screen during revolution of the grain from the hopper throughout the circumference of the casing I0 may drop. Such material dropping through the opening 51 will fall upon the lower'shelf 63 and be carried by the screen about the circumference of the casing into engagement with an outlet chute 69. The outlet chute 69 is provided in a break in the shelf 63 so that all of the material passing over the shelf 63 will be guided down this outlet chute 69.

In operation the grain to be cleaned passes into the hopper 44 and is fed through the adjustable gate 45 onto the shelf 65 between the screen 33 Rotation of the casing Ill causes friction against the grain which gradually moves the grain between the casing I0 and the screen 33 about the circumference of the casing until it drops through the opening 61 in the shelf 66. Any of the smaller particles'containe'd within the grain, such as the grain itself, the seeds, sand, chaff, dust and the like, pass through the screen 33 and drop between the deflector 32 and the sleeve 33. These elements spread the material into a thin cylindrical shield, dropping upon the seed screen 2|. As the material drops, air is blown from the outside through this cylindrical shield and the impurities are drawn between the deflectors 21 and 32 and out through the concentric sleeves to the aspirating chamber 53. The grain, seeds and heavy small impurities fall upon the seedscreen 2| where the seeds and small heavy impurities are separated from the grain by action of the agitators 26. The grain is withdrawn from the top of the screen through a suitable discharge opening While the grain falling through the screen drops upon the flooring Ill and is rotated by the spider |9 and the paddles been described in order to carry the highly banked grain to a portion of the cylinder where the grain is not banked so highly and to cause a rotation of the kernels of grain upon contact of the screen therewith.

The lower portion of the screen immediately above the shelf 65 is not provided with indentations so that any grain close to the shelf 65 is not carried at a high rate of speed around the circumference of the screen. This acts to provide a greater contact between the grain low on the shelf and the seed screen while the upper portion of the grain when banked deeply is agitated sufficiently by the indentations in the screen so that all of this highly banked grain hasan opportunity of contacting the screen and passing therethrough.

In accordance with the patent statutes I have described the principles of construction and operation of this grain separator, and while I have endeavored to set forth the best embodiments thereof, I desir to have it understood that these are only illustrative of a means of carrying out this invention and that obvious changes may be made within the scope of the following claims without departing from the spirit of the invention.

What is claimed is:

1. A screen for a grain separator including a cylindrical perforated body portion, the perforations of which are formed in rows, an imperiorated portion forming a closed band-like portion separating the upper rows of perforations from the lower rows of perforations, all of the rows of perforations below said imperforated band portion in said screen and some of the rows above said imperforated band portion of said screen being plain holes formed through the body of said screen, and all of the rest of the holes in the upper portion of said screen being formed with cup-shaped indentations partially extending around each of the holes, thereby providing a grain separating screen, the upper portion of which is formed with holes having projections on one side which act to draw or rake the grain in the direction of rotation of said screen in the grain separator while the plain holes above the imperforated band portion and below the same are smooth on the outer surface of the screen to decrease frictional contact of the screen with the grain pressing against the same.

2. A grain separator including an outer stationary casing, a perforated screen concentrically positioned within said casing, means for rotating said screen, a pair of horizontal ring-like shelves fixedly secured to said casing, the upper of said shelves having a hole therein to permit grainto pass directly from said upper shelf to said lower shelf, an imperforated band-like portion formed in said screen adapted to be contacted by a resilient band-like portion of said upper shelf, some of the holes above said upper shelf in said screen having cup-shaped indentations on one side thereof, while the other of the holes adjacent and above said upper shelf have a smooth outer surface to reduce the friction against the grain lying on said upper shelf, and all of the holes in the lower perforated portion of said shelf and above said lower shelf having a plain outer surface to reduce frictional contact with the grain introduced from the upper shelf onto the lower shelf.

OLGA A. MJOLSNESS, Emecutrim of the Estate of Haalcon Mjolsness,

Deceased. 

